The present invention relates to a method of producing images in a scanning apparatus. More particularly, the invention relates to an image producing method in which one-line components of multiple images can be obtained by one scanning operation.
As the conventional image producing means of obtaining one-line components of multiple images by one scanning operation, there is known a colour scanner for producing a plurality of colour separation images from a coloured original. In this conventional colour scanner, a coloured original to be reproduced is optically scanned and colour-separated to obtain a plurality of colour separation image signals indicating densities of respective colour components, and these colour separation image signals are separately stored in independent memory units. An exposing drum disposed on the image-reproducing side, on which a film to be exposed is wrapped, is circumferentially divided into equal sections. The number of the divided sections corresponds to the number of the above-mentioned colour separation image signals. Every time an exposing head passes through each boundary between adjacent division sections a section signal is produced, and the memory units for reading out the colour separation image signals are switched over in sequence in response to the so produced section signals. As a result, a plurality of images are produced along the circumferential direction of the exposing drum by the continuous scanning operation of the exposing head.
The first defect of this conventional technique is that, since each colour separation image signal is read out from the corresponding memory unit in response to the section signal, if the timing of production of the section signal is not in agreement with the timing of initiation of scanning, shear is caused in the produced images, and if the quantity of such shear is changed with the lapse of time, jitters occurs in the produced images.
The second defect of the above-mentioned conventional technique is that, since the memory units are arranged so that one memory unit is to store one kind of a colour separation image signal, it is impossible to produce images in a number larger than the predetermined number of the memory units disposed, and if the number of images produced is smaller than said predetermined number of the memory units, some of the memory units are not used for the reproduction and the storage capacity of the entire memory system is not effectively utilized.